support/export/export.c

   1 /*
   2  * support/export/export.c
   3  *
   4  * Maintain list of exported file systems.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include <config.h>
  11 #endif
  12
  13 #include <string.h>
  14 #include <sys/types.h>
  15 #include <sys/param.h>
  16 #include <netinet/in.h>
  17 #include <stdlib.h>
  18 #include "xmalloc.h"
  19 #include "nfslib.h"
  20 #include "exportfs.h"
  21
  22 exp_hash_table exportlist[MCL_MAXTYPES] = {{NULL, {{NULL,NULL}, }}, };
  23 static int export_hash(char *);
  24
  25 static void     export_init(nfs_export *exp, nfs_client *clp,
  26                                         struct exportent *nep);
  27 static int      export_check(nfs_export *, struct hostent *, char *);
  28 static nfs_export *
  29                 export_allowed_internal(struct hostent *hp, char *path);
  30
  31 static void warn_duplicated_exports(nfs_export *exp, struct exportent *eep)
  32 {
  33         if (exp->m_export.e_flags != eep->e_flags) {
  34                 xlog(L_ERROR, "incompatible duplicated export entries:");
  35                 xlog(L_ERROR, "\t%s:%s (0x%x) [IGNORED]", eep->e_hostname,
  36                                 eep->e_path, eep->e_flags);
  37                 xlog(L_ERROR, "\t%s:%s (0x%x)", exp->m_export.e_hostname,
  38                                 exp->m_export.e_path, exp->m_export.e_flags);
  39         } else {
  40                 xlog(L_ERROR, "duplicated export entries:");
  41                 xlog(L_ERROR, "\t%s:%s", eep->e_hostname, eep->e_path);
  42                 xlog(L_ERROR, "\t%s:%s", exp->m_export.e_hostname,
  43                                 exp->m_export.e_path);
  44         }
  45 }
  46
  47 int
  48 export_read(char *fname)
  49 {
  50         struct exportent        *eep;
  51         nfs_export              *exp;
  52
  53         setexportent(fname, "r");
  54         while ((eep = getexportent(0,1)) != NULL) {
  55                 exp = export_lookup(eep->e_hostname, eep->e_path, 0);
  56                 if (!exp)
  57                         export_create(eep, 0);
  58                 else
  59                         warn_duplicated_exports(exp, eep);
  60         }
  61         endexportent();
  62         return 0;
  63 }
  64
  65 /*
  66  * Create an in-core export struct from an export entry.
  67  */
  68 nfs_export *
  69 export_create(struct exportent *xep, int canonical)
  70 {
  71         nfs_client      *clp;
  72         nfs_export      *exp;
  73
  74         if (!(clp = client_lookup(xep->e_hostname, canonical))) {
  75                 /* bad export entry; complaint already logged */
  76                 return NULL;
  77         }
  78         exp = (nfs_export *) xmalloc(sizeof(*exp));
  79         export_init(exp, clp, xep);
  80         export_add(exp);
  81
  82         return exp;
  83 }
  84
  85 static void
  86 export_init(nfs_export *exp, nfs_client *clp, struct exportent *nep)
  87 {
  88         struct exportent        *e = &exp->m_export;
  89
  90         dupexportent(e, nep);
  91         if (nep->e_hostname)
  92                 e->e_hostname = xstrdup(nep->e_hostname);
  93
  94         exp->m_exported = 0;
  95         exp->m_xtabent = 0;
  96         exp->m_mayexport = 0;
  97         exp->m_changed = 0;
  98         exp->m_warned = 0;
  99         exp->m_client = clp;
 100         clp->m_count++;
 101 }
 102
 103 /*
 104  * Duplicate exports data. The in-core export struct retains the
 105  * original hostname from /etc/exports, while the in-core client struct
 106  * gets the newly found FQDN.
 107  */
 108 nfs_export *
 109 export_dup(nfs_export *exp, struct hostent *hp)
 110 {
 111         nfs_export              *new;
 112         nfs_client              *clp;
 113
 114         new = (nfs_export *) xmalloc(sizeof(*new));
 115         memcpy(new, exp, sizeof(*new));
 116         dupexportent(&new->m_export, &exp->m_export);
 117         if (exp->m_export.e_hostname)
 118                 new->m_export.e_hostname = xstrdup(exp->m_export.e_hostname);
 119         clp = client_dup(exp->m_client, hp);
 120         clp->m_count++;
 121         new->m_client = clp;
 122         new->m_mayexport = exp->m_mayexport;
 123         new->m_exported = 0;
 124         new->m_xtabent = 0;
 125         new->m_changed = 0;
 126         new->m_warned = 0;
 127         export_add(new);
 128
 129         return new;
 130 }
 131 /*
 132  * Add export entry to hash table
 133  */
 134 void
 135 export_add(nfs_export *exp)
 136 {
 137         exp_hash_table *p_tbl;
 138         exp_hash_entry *p_hen;
 139         nfs_export *p_next;
 140
 141         int type = exp->m_client->m_type;
 142         int pos;
 143
 144         pos = export_hash(exp->m_export.e_path);
 145         p_tbl = &(exportlist[type]); /* pointer to hash table */
 146         p_hen = &(p_tbl->entries[pos]); /* pointer to hash table entry */
 147
 148         if (!(p_hen->p_first)) { /* hash table entry is empty */
 149                 p_hen->p_first = exp;
 150                 p_hen->p_last  = exp;
 151
 152                 exp->m_next = p_tbl->p_head;
 153                 p_tbl->p_head = exp;
 154         } else { /* hash table entry is NOT empty */
 155                 p_next = p_hen->p_last->m_next;
 156                 p_hen->p_last->m_next = exp;
 157                 exp->m_next = p_next;
 158                 p_hen->p_last = exp;
 159         }
 160 }
 161
 162 nfs_export *
 163 export_find(struct hostent *hp, char *path)
 164 {
 165         nfs_export      *exp;
 166         int             i;
 167
 168         for (i = 0; i < MCL_MAXTYPES; i++) {
 169                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 170                         if (!export_check(exp, hp, path))
 171                                 continue;
 172                         if (exp->m_client->m_type == MCL_FQDN)
 173                                 return exp;
 174                         return export_dup(exp, hp);
 175                 }
 176         }
 177
 178         return NULL;
 179 }
 180
 181 static nfs_export *
 182 export_allowed_internal (struct hostent *hp, char *path)
 183 {
 184         nfs_export      *exp;
 185         int             i;
 186
 187         for (i = 0; i < MCL_MAXTYPES; i++) {
 188                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 189                         if (!exp->m_mayexport ||
 190                             !export_check(exp, hp, path))
 191                                 continue;
 192                         return exp;
 193                 }
 194         }
 195
 196         return NULL;
 197 }
 198
 199 nfs_export *
 200 export_allowed(struct hostent *hp, char *path)
 201 {
 202         nfs_export              *exp;
 203         char                    epath[MAXPATHLEN+1];
 204         char                    *p = NULL;
 205
 206         if (path [0] != '/') return NULL;
 207
 208         strncpy(epath, path, sizeof (epath) - 1);
 209         epath[sizeof (epath) - 1] = '\0';
 210
 211         /* Try the longest matching exported pathname. */
 212         while (1) {
 213                 exp = export_allowed_internal (hp, epath);
 214                 if (exp)
 215                         return exp;
 216                 /* We have to treat the root, "/", specially. */
 217                 if (p == &epath[1]) break;
 218                 p = strrchr(epath, '/');
 219                 if (p == epath) p++;
 220                 *p = '\0';
 221         }
 222
 223         return NULL;
 224 }
 225
 226 /*
 227  * Search hash table for export entry.
 228  */
 229 nfs_export *
 230 export_lookup(char *hname, char *path, int canonical)
 231 {
 232         nfs_client *clp;
 233         nfs_export *exp;
 234         exp_hash_entry *p_hen;
 235
 236         int pos;
 237
 238         clp = client_lookup(hname, canonical);
 239         if(clp == NULL)
 240                 return NULL;
 241
 242         pos = export_hash(path);
 243         p_hen = &(exportlist[clp->m_type].entries[pos]);
 244         for(exp = p_hen->p_first; exp && (exp != p_hen->p_last->m_next);
 245                         exp = exp->m_next) {
 246                 if (exp->m_client == clp && !strcmp(exp->m_export.e_path, path)) {
 247                         return exp;
 248                 }
 249         }
 250         return NULL;
 251 }
 252
 253 static int
 254 export_check(nfs_export *exp, struct hostent *hp, char *path)
 255 {
 256         if (strcmp(path, exp->m_export.e_path))
 257                 return 0;
 258
 259         return client_check(exp->m_client, hp);
 260 }
 261
 262 void
 263 export_freeall(void)
 264 {
 265         nfs_export      *exp, *nxt;
 266         int             i, j;
 267
 268         for (i = 0; i < MCL_MAXTYPES; i++) {
 269                 for (exp = exportlist[i].p_head; exp; exp = nxt) {
 270                         nxt = exp->m_next;
 271                         client_release(exp->m_client);
 272                         if (exp->m_export.e_squids)
 273                                 xfree(exp->m_export.e_squids);
 274                         if (exp->m_export.e_sqgids)
 275                                 xfree(exp->m_export.e_sqgids);
 276                         if (exp->m_export.e_mountpoint)
 277                                 free(exp->m_export.e_mountpoint);
 278                         if (exp->m_export.e_fslocdata)
 279                                 xfree(exp->m_export.e_fslocdata);
 280                         xfree(exp->m_export.e_hostname);
 281                         xfree(exp);
 282                 }
 283       for(j = 0; j < HASH_TABLE_SIZE; j++) {
 284         exportlist[i].entries[j].p_first = NULL;
 285         exportlist[i].entries[j].p_last = NULL;
 286       }
 287       exportlist[i].p_head = NULL;
 288         }
 289         client_freeall();
 290 }
 291
 292 /*
 293  * Compute and returns integer from string.
 294  * Note: Its understood the smae integers can be same for
 295  *       different strings, but it should not matter.
 296  */
 297 static unsigned int
 298 strtoint(char *str)
 299 {
 300         int i = 0;
 301         unsigned int n = 0;
 302
 303         while ( str[i] != '\0') {
 304                 n+=((int)str[i])*i;
 305                 i++;
 306         }
 307         return n;
 308 }
 309
 310 /*
 311  * Hash function
 312  */
 313 static int
 314 export_hash(char *str)
 315 {
 316         int num = strtoint(str);
 317
 318         return num % HASH_TABLE_SIZE;
 319 }